The Importance of the Vagus Nerve

By Michelle Parker, D.C.

The vagus nerve is the tenth cranial nerve, and has the most extensive distribution out of all of the cranial nerves. Named for its tendency to wander, the vagus nerve acts like a central switchboard, sending out nerve impulses to and from the brain and most of the organs in our body. Its main role is to calm us down by activating the parasympathetic nervous system. 

The vagus nerve, derived from the brainstem, is diverse, providing sensory, special sensory, motor, and parasympathetic innervations. The human brain extends down to form the brainstem and then to form the spinal cord. The brainstem controls and regulates vital body functions such as respiration, heart rate, and blood pressure. The vagus nerve emerges from the brainstem, exiting the skull through a small opening called the jugular foramen. From there, it reaches the ears, throat (pharynx and larynx), tongue, stomach, intestines, heart, liver, spleen, pancreas, gallbladder, kidneys, ureter, and reproductive organs. Research continues to reveal even more. 

Conditions resulting from vagus nerve impairment are numerous and diverse. Starting with the brain, some of the most common disorders are anxiety and depression, which can be traced directly to the vagus nerve. Sensations of the middle and external ears are performed by it. Disturbing this ear pathway can contribute to ringing in the ears (tinnitus). The vagus nerve is responsible for the swallowing and the gag reflex of the pharyngeal muscles. Hoarseness or dysphagia (difficulty in swallowing) can be present with impairment of the vagus nerve. 

The vagus nerve also innervates the laryngeal muscles, known as the voice box. Abnormal articulation of speech, such as dysarthria, may also arise with vagus nerve disorders. Disorders of speech and swallowing can be very disabling, or even fatal. In the tongue, the vagus nerve is involved in the ability to taste and to produce saliva, which initiates proper digestion of food. In the stomach, the vagus nerve increases stomach acidity, digestive secretions, and gut flow. Having less vagus activation can increase the chances of irritable bowel syndrome (IBS). Vagus nerve stimulation enhances the release of histamine in stomach cells, which releases stomach acid. Low stomach acidity is partially a vagus nerve issue. Disorders related to low stomach acidity include gastroesophageal reflux disease (GERD), heartburn, inflammatory bowel diseases such as Crohn’s and ulcerative colitis (UC), and gastroparesis (stomach paralysis).

Parasympathetic stimulation of the vagus nerve intensifies the muscle tone, strength, and peristalsis of the intestines. 

Research on vagus tone (response) suggests vagal activation to be associated with infant growth and weight gain. In a study of preterm infants, researchers found an enhancement of gastric motility by stimulating vagus activity, leading to more efficient food absorption and ultimately greater weight gain. At the heart of the matter, the vagus nerve controls heart rate and blood pressure. Vagus stimulation will decrease the risk of heart disease. Reinforced vagus nerve tone enhances general kidney function by increasing blood flow filtration, releasing amounts of dopamine in the kidneys, and excreting sodium—and by doing so, lowers blood pressure. It is well-documented that vagus nerve activation will release acetylcholine, which decreases inflammation in targeted organs. However, when mobilized in the spleen specifically, the overall inflammation response is more systemic. Additionally, our reproductive organs are affected by it; for women, this involves the cervix, uterus, and vagina, thereby playing a major role in fertility. 

If we can learn to stimulate the vagus nerve, we can promote calmness and a better sense of harmony in our nervous system, allowing the body to “rest-and-digest,” which, in turn, promotes healing, growth, and joy. The strength of the vagus response can be measured by heart rate variability (HRV). 

It is not surprising that vagus nerve impairment can wreak havoc on many organ systems, creating numerous devastating conditions and problems. 

The Paradox of Balance 

Life is not and cannot be perfect. Peter Kevorkian, D.C., a brilliant doctor, husband, and father, said this during a presentation I attended: “You mothers need to stop trying to find balance in life. You will never find it.” 

I thought that Dr. Peter had lost his mind. He stood in front of a classroom, evenly on both feet, with correct posture, silent and still. He explained that he had found the perfect balance at that moment in time, but if he wanted to move forward, he would need to lift one of his arms, start raising his opposite leg, contract certain muscles and lengthen others, in order to physically take a step. There he stood, one leg in front of the other, imbalanced, but in a stance poised to move forward. 

I will never forget this presentation. Well-adjusted people do not necessarily have less stress in their lives. Their nervous systems are just better equipped to handle the demands required to move forward. They have learned methods and actively do things that help manage their stress and increase their flexibility. 

This is the power of chiropractic. By eliminating interferences within the cranium and spine, chiropractors help us find our body’s natural harmony, what nature created for our survival—our innate intelligence. 

Pain can be a signal for positive change. When we feel like the world is pressing in, let’s remember what lies behind that feeling. The vagus nerve, and the nervous system at large, innervates all body systems, including those underpinning social interactions, and we truly can reach a life of freedom, joy, and wholesome wellness if we appreciate the ways we can bring our nervous systems into alignment.

Excerpted from Pathways to Family Wellness. Read the full article.